Polymerization of allylic ethers



Patented Dec. 30, 1952 s PATENT OFFICE 2,623,864 POLYMER-IZATION F ALLYLIO ETHERS Arthur N. Wrigley and Elias Yanovsky, Philadelphia, and Peter L. signors resented by the Nichols, Jr., Oreland, Pa., asto the United States of America as rep- Secretary of Agriculture N0 Drawing. Application July 29, 1949, Serial No. 107,624

8 Claims. (01. zed-17.4)

ct of March 3, 1883, as 1928; 370 O. G. 757) (Granted under the a amended April 30,

This application is a continuation in part of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented in any country, may be manufactured and used by or for the Government of the United States of America for governmental purposes throughout the world without the payment to us of any royalty thereon..

This application is a continuation in part of our copending abandoned application Serial No. 648,550 filed February 18, 1946.

This invention relates to polymeric products derived from organic solvent soluble allylic ethers and has among its such polymers and processes for their preparation. Polymerizable organic solvent soluble allylic ethers of aliphatic polyhydric compounds include:

1. Solid allylic ethers of polymeric polyhydroxy compounds such as starch, and

2. Liquid allylic ethers of monomeric polyhydroxy compounds like glycols, glycerol, mannitol, sucrose, etc.

These solid and liquid allylic ethers possess the valuable property of being modified on contact with air (or oxygen) and converted, slowly at ordinary temperature and more rapidly on heating, to insoluble, infusible solid products which ar highly resistant to the action of heat, solvents and other reagents. in the case of the solid ethers results in an insolubilization, and in the case of the liquid ethers causes solidification as well as insolubilization, will hereinafter be referred to as polymerization, regardless of the agents used to induce it or to the probable mechanism of the reactions involved.

Polymerization of allylic ethers on contact with free oxygen, is promoted by application of heat, ultra-violet or infra-red radiations and the presence of conventional paint driers. However, only films or thin coatings can thus be polymerized and completion of the process'usually requires a considerable length of time.

When such polymerization procedures are applied to the treatment of a thick layer, or a relatively large body of the ether, polymerization occurs only on the surface thereof, while the inner portion, out of contact with atmospheric oxygen, remains essentially unchanged, irrespective of the temperature and duration of the process. Attempts to overcome this difficulty by incorporating into the ether an oxygen-yielding substance were unsuccessful. It was then found that the solid, polymerizable ethers such asallyl This process, which A objects the provision of I starch can be uniformly polymerized by heating in the mold with sulfur and rubber compounding ingredients. This process described in Patent No. 2,449,816 to Nichols and Hamilton,has the following limitations.

1. The products are opaque due to the use of free sulfur and other ingredients.

2. Liquid ethers are not well adapted for use since they cannot be satisfactorily compounded.

3. It is impracticable to use the method for the production of coatings.

We have found that allylic ethers react with a sulfur chloride, such as sulfur monochloride or sulfur dichloride, to form polymeric products. We have also found that the degree of polymerization thus attained can be controlled within wide limits by varying the sulfur chloride-allylic ether ratio utilized in th process. We have further found that organic solvent soluble, polymerizable allylic ethers of aliphatic polyhydric compounds can thus be rapidly and uniformly polymerized, either in bulk or in the form of thin layers, and converted into infusible and insoluble products.

Polymerization of the allylic ethers. by the method of our invention is induced by contact with the sulfur chloride and can be effected by mixing the reactants, as such or in the presence of an inert solvent or diluent. Films, coatings and other thin layers of the allylic ethers can also be polymerized by exposure to vapors of sulfur chloride. i

The reaction between allylic ethers and the sulfur monochloride or sulfur dichloride is a violent one, but can be moderated by proper regulation of the concentration of the reacting substances. Although polymerization products can be obtained at elevated temperature, for instance at about 0., low temperature favors better control of the reaction and purity of the resulting products in that degradation of the glycosidic linkages of those etherswhich contain them is avoided. We prefer therefore, to conduct bulk polymerization of allylic ethers at temperatures below 40 C., and preferably with in the range of about 0 to 25 C. in reactions involving ethers containing glycosidic linkages. At temperatures substantially below 0 C. the reaction rate is greatly decreased.

The polymerization method of this invention is applicable to solvent soluble allyl and substitutedallyl ethers, such as allyl, methallyl, crotyl, cinnamyl, chloroallyl or bromoallyl ethers, and in general to organic solvent soluble allylic ethers containing more than one allylic ether group,

that is an oxygen bonded carbon-chain radical of an monounsaturated beta-gamma olefinic alcohol, having theigeneral formula:

two to eight hydroxyl groups, like ethyleneiglycor and other glycols; glycerol, pentaerythritohmane nitol and other hexitols, sucrose etc;'; and of 'solid' allylic polyethers of oligosaccharides and polysaccharides, containing at least 1.3 allylic groups per hexose unit and adapted to form, at ordi nary temperature, solutions in organicsolvents',

like acetone, alcohols, benzene, toluene, or'xylene, of at least about 40 percent concentration, such as allylic polyethers of starch. In View of their ready availability and the superior products" had therewith,we prefer to use 'in'our'process those ethers-in which the allylic group are allyl or Z-nieth'yl allyl group, such as theallylic ethers described in Journal of American Chemistry? Society, 66, 1625-1627 (1944) 67, 46-49; 2037- 2039 (1945) 68,'2020'-'2022'(l94'6).

In the bulk polymerization of allylic ethe'rs we prefer to'u'se the sulfur-"chl-oride'and the "ether in the" molar ratio of at'lea'stl to 2. By varying the sulfur chloride-allylic e'ther' ratio' the bulkpolymerization process"- makes possible-to control the extent bi' polymerization er the resultingfprodu'ct s', and to obtain various polymericmaterials useful as components an'dintei mediate in the production or plasticizers and modi'fying agents, adhesives, synthetic resins, andsimlilar constituents of "plastic and coating compositions.

' The following examples illustrate theinvention.

EXAMPLEI Tengrams of diallyl ether were 'pla'ced in'to a flask provided with a dropping funne meehanical stirrer and a chlorcalcium tube. 6188 grams of sulfur monochloride (an amount -suflicient to react-with one a-llyl group per eacli moleculeof the allyl ether) Wasadded through the dropping funnel with agitation and while maintaining the temperature of the reaction mixture at25 C; by means 'of external cooling. When-the exothermic reaction had subsided, the contents ofthe fiask were held at room temperature for twenty hours. The almost colorless, mobile liquid-thus obtained was soluble in benzene, carbon disulfide, acetone, ethyl ether, ethyl acetate, chloroform and dioxane'. A-similar product was obtained by combin mg the reactants at 0 Cl and maintaining at zero degrees for-7 hours.

Ten giems of diallylf 'e'ther treated ait o c. with 12.39 'grains 'of sulfur monochloride renougn for 1Z8"all yl g'roups) asdescribed in the foregoing exampie gave arr-extremelyviscous;clear 'yellow preduedsemme: in' most organic "solvents other than alcohol, ether or aliphatic-hydrocarbons.

EXAMPLE III Ten grams of diallyl'ether'were reacted at'25' C. with 13.8 grams sulfur monochloride (enough for two" allyl groups) as'described iirExample I. After'fi've' hours the reactionmixture was converted to" a product having: molasses-like consistency, and: on standing" for an additional seventy tw'o-hours' at room temperature," apale 't'etramine at "verted'to'a benzene insoluble material.

4 yellow, semi-solid material was formed which was soluble in benzene, carbon disulfide, ethyl acetate, chloroform and dioxane; partly soluble in acetone and insoluble in water, ethanol; ether, allyl mannitol andparaffinic' hydrocarbon solvents. When this product was heated in triethylene C. for one hour, it was con- EX'AMPLE IV Tw'enty-gramsof diallyl ethylene glycol were reacted -witha nineteen grams of sulfur monochloride (enough for two allyl groups) at 25 C. as described in the foregoing examples. The

'-sulfur-monochloride was added in two equal increments-at two hour intervals. The exothermic reaction was completed within five hours after which time the vi'scosity of the reaction mixture -ceased'-" to increase to any appreciable degree. The mixture was then allowed to stand overnight at room temperature. The viscouspi'odu'ct thus obtained was soluble" in toluene andone part of'a 26% solution in this solvent whenblended with ,fourparts by volume of a 26% solution of allyl starch' in toluene, formed clear, homogeneous mixture;- films deposited from this mixture on wood panels wereclear'and" showed good com patibility. A similar yellowish, sirupyproduct was obtained on adding" 9.5 :grams'cf" sulfur monochloride'to 10 'grazns of 'diallylethylene glycol over a period of? minutes, withzagitation and while maintaining 'the'tempera'ture at 25 C., stirring the mixture for an additional 4. /2.;hOl1IS and then-allowing it to stand' at roomitemperature for 24= hoursi The products r obtained' byeither of the abovedescribed 'procedur'es showed the same solubility in organic solvents as that displayed by the'prodnot of Example III, and were similarly rendered insoluble in benzeneby heating with triethylene tetramine.

EXAMPLE V Ten grams of triallyl glycerol. were stirred with3;l8 grams-of'sulfur monochloride. (enough for'oneallyl group) which wasadded allat once Ten grams" of triallyl glycerol were reacted with 5.3 grams of sulfur monochloride (enough for 11.5 allyl groups) as 'descr-ibe'd in the foregoing example? The resulting product was" a" thick, sirupyi material insolublein ethanol, pa'rafiinic hydrocarbons and glacial acetic acid, but soluble in the othersolventslistedin-Example V.

- EXAMPLE VII Ten' .1 grams" of triallyl glycerol were reacted with 556- grams of sulfur monochloride (enough for 1175'allyl groups) as described in Example V. The very viscous product so obtained was soluble in many of 'the'comm'on organic solvents. Films prepared from solutions obtained by blending a 30% 's'olution'of this material-in toluene with 4 parts of 30% toluene solution of allyl starch showed complete compatibility.

EXAMPLE VIII Ten grams of triallyl glycerol were reacted with 6.36 grams of sulfur monochloride (enough for 2 allyl groups) which was added over a period of 5 minutes, while stirring and maintaining the temperature at 25 C. Within 2% hours the reaction mixture was converted into analmost colorless crumbly solid which was insoluble in carbon disulfide, acetone, ethanol, ether, ethyl acetate, chloroform, dioxane, paraflinic hydrocarbons, and monomeric allyl mannitol, and swelled in benzene.

EXAMPLE IX Eight grams of triallyl glycerol were reacted with 7.63 grams of sulfur monochloride (enough for three allyl groups) by mixing the reactants with agitation while maintaining the temperature at about 25 C. Within half an hour the reaction mixture was converted to a hard, amberlike resinous solid that was insoluble in all common organic solvents.

EXAMPLE X Ten grams hexaallyl mannitol were reacted at 25 C. with 2.7 grams of sulfur monochloride (enough for 1.5 allyl groups). The product so obtained was an insoluble solid which swelled in benzene, carbon disulfide, acetone, ether, ethyl acetate, dioxane and allyl mannitol, but was completely insoluble in ethanol and paraflinic hydrocarbons.

EXAMPLE XII Ten grams of hexaallyl mannitol were reacted at 25 C. with 3.19 grams sulfur monochloride (enough to react with two allyl groups). After stirring for one hour the liquid mixture was converted to a pale yellow powder. It was insoluble in acetone, ethanol, ethyl acetate, ether; swelled by benzene, xylene, chloroform, carbon tetrachloride, carbon disulfide, and dioxane. On a hot-stage melting point apparatus this product did not melt, but slow decomposition set in at 230 C. This product contains 13.5% sulfur and 13.6% chlorine.

EXAMPLE XIII Ten grams of hexaallyl mannitol were reacted at 25 C. with 6.38 grams of sulfur monochloride (enough for 4 allyl groups). In thirty minutes the reaction mixture was converted into a dark brown resinous mass which was insoluble in organic solvents.

EXAMPLE XIV The procedure of Example XHI was repeated, but the temperature of the reaction mixture was maintained at 0 C. A yellow, optically clear, tough glass-like material of strong adhesion to 6* the glass vessel was formed. This product was insoluble in benzene and acetone.

EXAMPLE XV A mixture of ten grams hexaallyl mannitol and 6.38 grams sulfur monochloride were placed in a large test tube; and a smaller test tube, through which ice water flowed was set inside the first test tube so as to provide a cool inner surface in contact with the reaction mixture. The larger test tube was placed in an ice water bath. After twenty-four hours the reaction mixture solidified to a hard, brilliantly clear, yellow resin which adhered tenaciously to the glass walls of the vessels. When the glass was broken and separated with difficulty from the polymer, a hard, bright surface was exposed which resisted attack by laboratory air or water.

EXAMP E XVI Ten grams of tetraallyl pentaerythritol treated with 9.13 grams of sulfur monochloride (enough for four allyl groups) at 0 C. gave a tough, fairly hard, pale yellow solid which was infusible and insoluble in all common organic solvents.

EXAMPLE XVII Ten grams of hexaallyl dipentaerythritol treated with 5.46 grams of sulfur monochloride (enough for four allyl groups) at 0 C. yielded a product similar to that of Example XVI.

EXAMPLE XVIII 2.32 grams of sulfur monochloride dissolved in 5 ml. of toluene were added at room temperature to 20 grams of a 25% solution of allyl starch in toluene with swirling to prevent local precipitation. The flask containing the mixture was then stoppered and placed in an ice water bath. The mixture solidified after fifteen minutes. After allowing the flask to stand overnight in a cold room, the stopper was removed and the toluene evaporated spontaneously at room temperature. The solid residue was easily broken; it was insoluble in benzene and acetone.

EXAMPLE XIX Allyl starch, containing about two allyl groups per glucose unit, was dissolved in benzene to form a solution containing 16 parts of allyl starch per 100 units of solution. Wooden panels were given two brushed-on coats of this benzene solution of allyl starch, and after the panels became dry to the touch (evaporation of the solvent), they were placed in a desiccator containing a dish of sulfur chloride. After about 5 hours at room temperature, thepanels were removed from the desiccator. On rubbing the film with acetonesoaked cloth, it showed no solubility in acetone.

EXAMPLE ICC To a solution of allyl starch containing about two allyl groups per glucose unit, in benzene, a benzene solution of sulfur monochloride was added to give a solution containing sulfur monochloride and allylstarch in the approximate ratio of 8:5. Wooden panels coated with this solution were air-dried at room temperature, and after about 3%; hours, the coat was found to be insoluble in acetone.

EXAMPLE XXI Coats on wooden panels prepared as in Example XX became insoluble in about 10 minutes after drying in a forced-draft oven at C.

7. EXAMPLE'XXII, One coat of allyl sucrose (about 45% allyl or 7 allyl groups), was, appliedltopa-nels which were subsequently keptina desiccator containing a dish. of su1fu1, monochloride. After about. 7 hoursgat, room temperature, the coatingwasinsolubleinacetone, whereas the control, kept" for thesame time, wasstill wet to the touch.

EXAMPLE XXIII Wooden panels were coated with methallyl mannitol (about63% methallyl or 5.5 methallyl groups), and-exposed to vapors of 'sulfurchloride in the manner described in Example XIX. After 5--hours exposure at room temperature, the coat was insoluble in acetone.

Quantitative experiments on the insolubilization of allyl starch films yielded the following results, in which'Table 1* indicates the results obtained using sulfur monochloride (SzClz), and Table II illustrates the results obtained using sulfur dichloride vapor (S012) Table I Percent insoluble Ratio of mols of sulfur' monochlorido material after- (S2012) to mols of diallyl starch N 3 hours 6 hours Percent in- Time of ex 7 posure, Min. fig g r I i g 120 I 97 180 a 99 I I We claim:

1. A process comprising reacting a solvent soluble allyl ether containing a plurality of allyl other groups and inbulk form with a sulfur chloride by forming a mixture of said reactants wherein the molar ratio of the sulfur chloride to. the. ether is at least 1 to 2, and allowing the reaction. to proceed tosubstantial completion at a temperature of about from 0 to 25 C.

2. The, process of claim 1 wherein. the sulfur chloride. is sulfur monochloride.

3. A process comprising reacting a solventsoluble, aliphatic allylic, ether containing a plurality of allylic ether groups and selected from chlorideby formin a 81 the group consisting of allylstarch and allyl sucrosewith a sulfur. chlorideand allowing the reaction .to, proceed to substantial completion at a temperaturebelow about C.

A- Aprocesscomprising rcactinga solvent sol:

uble allylhether of starch containinga plurality of rallylicretherrgroups with a sulfur chloride ,and'

ether groups; inbulk form, and selected from the group consisting of allyl starch and allylsucrose with a sulfur .ChlOlidG'bY fOlllliIlg a mixture of saidreactants wherein the molar ratio of thesulfur chloride to the ether is at least 1 m2, and allowing the reaction to proceed to substantial completion at a temperature below about 40- C.

'7. A process comprising reacting solvent solubleallyl starch containing a plurality of allyl ether groups and in bulk form with asulfur chloride by forming a mixture of said reactants wherein themolarratioof the sulfurchloride to the ether is at least 1' to 2,- and allowing the reaction to proceed to substantial completion at a temperature below about 40 C.

8. A process comprising reactingsolvent soluble allyl sucrose containing a plurality; ofallyl other groups and in' bulk form with a sulfur I mixture of said reactants wherein themolar'ratio of thesulfur chlorideto the'ether is at least 1' to 2, and allowing thereaction to proceed to substantial completion at a temperature below about 40 C.

ARTHUR N. WRIGLEY. ELIAS YANOVSKY. PETER'L. NICHOLS, JR.

REFERENCES. CITED The following references are of recordzinthe file of this patent:

UNITED STATES PA'IENTS OTHER- REFERENCES Nichols et al., Ind, 8.: Eng. Chem., Feb. 1945, pp. 201-202.

Nichols et al;,

Official Digest, Mar.'19 l5, pp. 111-123: 

7. A PROCESS COMPRISING REACTING SOLVENT SOLUBLE ALLYL STARCH CONTAINING A PLURALITY OF ALLYL ETHER GROUPS AND IN BULK FORM WITH A SULFUR CHLORIDE BY FORMING A MIXTURE OF SAID REACTANTS WHEREIN THE MOLAR RATIO OF THE SULFUR CHLORIDE TO THE ETHER IS AT LEAST 1 TO 2, AND ALLOWING THE REACTION TO PROCEED TO SUBSTANTIAL COMPLETION AT A TEMPERATURE BELOW ABOUT 40* C. 